Gastroesophageal reflux disease (GERD) represents a host of symptoms and pathologies believed to result from the inappropriate exposure of the esophagus and upper airway to gastric acid. A wide host of diseases are attributed to this exposure, ranging from esophageal injury to the wide host of disorders termed “laryngopharyngeal reflux”.
As is disclosed in U.S. Pat. No. 6,725,866; “Current methods to treat gastroesophageal reflux disease consist of lifestyle changes such as weight loss, avoidance of certain foods that exacerbate the symptoms of GERD and avoidance of excessive bending. Elevation of the head of the bed helps prevent nocturnal reflux. While these avoidance strategies may be helpful, there is relatively little data supporting the efficacy of lifestyle modification alone for the treatment of GERD. Medications for the treatment of GERD have been administered for years with little or no success.” One symptom of GERD mentioned in the above referenced patent is dyspepsia. “Dyspepsia, or heartburn, is defined as a burning sensation or discomfort behind the breastbone or sternum and is the most common symptom of GERD. Other symptoms of GERD include dysphasia, odynophagia, hemorrhage, water brash, and pulmonary manifestations such as asthma, coughing or intermittent wheezing due to acid aspiration. Dyspepsia may also mimic the symptoms of a myocardial infarction or severe angina pectoris.” GERD has also been linked to irregularities in the upper airways, such as asthma. It is believed that the low levels of acid released due to GERD are responsible for these irregularities. It is often difficult to properly diagnose GERD, as many other conditions mimic the symptoms of GERD. As is taught in U.S. Pat. No. 5,951,468 “since the symptoms of GERD often mimic cardiac chest pain, the physician must confirm that the symptoms are in fact due to reflux and not to a cardiac condition.”
U.S. Pat. No. 4,168,703 teaches an alternative testing conditions involve the monitoring the pressure within the lower esophagus. This testing procedure is deficient due to the substantial degree of patient discomfort involved with this method.
U.S. Pat. Nos. 4,503,859 and 5,117,827 teach a procedure to test for reflux which includes esophageal pH monitoring, with esophageal manometry testing. This testing occurs by passing a catheter into the esophagus, and then monitoring pH and sphincter pressures for 24 hours through the use of an ambulatory monitoring device. Test results are then analyzed to determine reflux degree. Such ambulatory devices are extremely inconvenient for the patient. In addition, these testing conditions require a significant amount of time to obtain a result.
U.S. Pat. No. 5,254,591 discloses a pharmaceutical composition useful for treating gastroesophageal reflux disease. This patent clearly fails to disclose or suggest a method of detection for the disease.
U.S. Pat. No. 5,524,622 teaches a method of detecting increased blood flow to certain regions of the gastrointestinal tract, and thus is able to detect inflammation of the tract. This technique is deficient in that it is significantly more complex and considerably more expensive that that of the instant invention. The equipment needed to conduct such testing is exceedingly specialized.
U.S. Pat. No. 5,571,116 discloses a minimally invasive device and method for the treatment of gastroesophageal reflux disease. The techniques taught in this patent may be used in conjunction with the instant invention. However, this patent fails to disclose a method of detection of gastroesophageal reflux disease.
U.S. Pat. No. 5,738,110 teaches a retrievable capsule useful for obtaining samples of gastroesophegeal fluids. In this manner, epithelial cells may be removed for later testing. While this patent teaches methods of obtaining samples for testing, it fails to teach testing methodology itself.
U.S. Pat. No. 5,879,897 teaches an immunoassay technique for the detection of pepsin. This patent provides “ . . . methods of detecting and diagnosing reflux diseases and disorders by detecting the presence of pepsin in airway secretions (e.g. throat, lung, esophagus, or mouth mucus/sputum/saliva) or other bodily fluids of subjects suspected of having a reflux disorder of disease. An advantage of the disclosed methods over methods based on detection of pH changes is that pepsin or pepsinogen from reflux becomes trapped in the mucus and remains in the throat or esophagus longer than acid (hydrogen ions) and can thus be detected for hours or days after a reflux event.” The techniques taught in U.S. Pat. No. 5,879,897 can be distinguished from the instant invention by the nature of the detection system itself. The instant invention, in one embodiment, detects the enzymatic activity of pepsin. The aforementioned antibody techniques are deficient in that they detect pepsin itself, even when such pepsin may not be an active enzyme. Additionally, such immunoassay techniques are known to take a significant amount of time to obtain results.
U.S. Pat. No. 5,951,468 discloses a method for testing for esophageal acid sensitivity by attempting to induce the symptoms of gastroesophageal reflux through the ingestion of weak acids. This patent is clearly distinguished from the instant invention by the very nature of the test.
U.S. Pat. No. 6,238,335 teaches a method and device for the treatment of gastroesophageal reflux disease. The techniques taught in this application involve the augmentation of the epithelial lining to promote acid resistance.
U.S. Pat. No. 6,338,345 discloses a device and method for the delivery of treatment agents into the esophagus for the treatment of gastroesophageal reflux disease. Both of these patents fail to teach or suggest a method of testing for gastroesophageal reflux disease.
U.S. Pat. No. 6,475,145 teaches a method for monitoring pH levels over a prolonged period of time. The techniques of this patent are deficient in that they fail to teach or suggest a rapid testing method for the detection of gastroesophageal reflux disease.
U.S. patent application 2004/0002168 discloses a test strip to test for cerebrospinal fluid. This application contains no suggestion or motivation to modify this test strip to test for pepsin. Other test strips and/or test strip reading devices are disclosed in U.S. Pat. No. 6,180,063 (Measuring Device for Use with a Test Strip); U.S. Pat. No. 6,315,951 (Test Strip Measuring System); U.S. Pat. No. 6,514,460 (Luminous Glucose Monitoring Device); U.S. Pat. Nos. 6,514,461 and 6,716,393 (System for Automatically Testing a Fluid Specimen); U.S. Pat. No. 6,689,320 (Test Strip Measuring System); and the like.
The content of U.S. Pat. Nos. 4,168,703; 4,455,381; 4,503,859; 5,117,827; 5,254,591; 5,524,622; 5,571,116; 5,738,110; 5,879,897; 5,951,468; 6,180,063; 6,238,335; 6,315,951; 6,338,345; 6,475,145; 6,514,461; 6,689,320; 6,716,393; 6,725,866 and U.S. patent application 2004/0002168 is hereby incorporated by reference into this specification.
Yet another testing method involves nasogastric intubation of the patient and subsequently adding dilute acid to intentionally trigger the condition to be tested for. As is known to those skilled in the art, this test is often referred to as the “Berstein acid perfusion test.”
As acknowledged in U.S. Pat. No. 5,951,468 “Currently, there is no simple diagnostic test or procedure that can be done either in a physician's office or in an individual's home to assist with the diagnosis of acid reflux and GERD.”
It is an object of this invention to provide at least one of the following; a method for the detection of an enzyme that is rapid and convenient enough that it can be performed in a physician's office or similar location without the need for ambulatory monitoring devices; a method for detecting an enzyme wherein the enzyme can be detected in less than two hours (i.e. “point of care” detection).